Abstract
Because the loose circle is an important basis and parameter for designing the tunnel support and estimating whole stability, how to determine its area accurately and fast has become all issues of concern. In this paper, combined with the actual situation, and used the visualization technology, we test the surrounding rock loose circle of roadway, which in 10-1# and 8# coal seam. The test results show that the measurement of surrounding rock loose circle borehole camera technology is reliable, and the thickness of the broken rock zone varies with the measuring position within a cross section of the roadway. And the 10-1 # coal seam loose ring size is 1.1 -1.6 m, 8 # seam loose ring size is 1.4~1.8 m, safe coal loose circle range between loose circle in the big and loose circle. Besides, the study results have some consult effects on the similar engineering.
